Replacing Mitsumi Keycaps

Tools

Black stick (Apple part number 922-5065) or other nonconductive nylon or plastic flatblade tool

Fine-point tweezers

Needlenose pliers

Preliminary Steps

Before you begin, remove the battery.

Part Location

The Mitsumi keyboard comes in three versions: ANSI, ISO, and JIS. Refer to the following keyboard layouts to help identify them.

ANSI Keyboard Layout:

ISO Keyboard Layout:

JIS Keyboard Layout:

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f Of

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1 ' U 3 " | » a ( m

i % & ¡6 1 ^ | 5 Í 6 3 i: J 33

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5 :s control ¿

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Like the Darfon keyboard, the Mitsumi keyboard is integrated in the top case and cannot be removed from the top case. The Mitsumi keyboard comes in three versions: ANSI, ISO, and JIS. The square keycaps for all three versions use the same dual-hinge mechanism inside the keycap well with one stabilizer bar inside the keycap.

For the Space bar replacement, the ANSI and ISO Space bar keycaps look the same: two singlehinge mechanisms and two stabilizer bars in the keycap well. The JIS Space bar keycap, by contrast, has two dual-hinge mechanisms and two stabilizer bars.

Once you are experienced replacing square keycaps and the Space bar, you can easily replace other size keys because of their shared traits. For example, the ANSI Return keycap has a dual-

hinge mechanism and one stabilizer bar; whereas the ISO and JIS Return keycap has no hinge mechanism and three stabilizer bars.

Important Tips:

Before installing a new keycap, make sure

The clips on the underside of the keycap are not broken or bent.

The hinge mechanism operates smoothly.

The stabilizer bar is fully snapped into place

The hinge mechanism is closed and slid farthest from the rubber dome before lowering the keycap over the keyboard well.

Removing and Replacing a Square Key

1. If a key needs to be removed (for example, if a key is sticking when pressed), pry it up from the

Because adhesive is used under the top case, closely inspect the case for any adhesive that may have built up under the keycap. Lift away any built-up adhesive using fine-point tweezers.

Note the stabilizer bar and clips on the underside of the keycap, and check that the dual-hinge mechanism lays flat.

4. Test the operation of the dual-hinge mechanism by using a black stick to carefully raise and lower the mechanism.

If it is installed correctly, the hinged pieces should move smoothly.

If it is damaged or loose, refer to the section "Reassembling the Hinge Mechanism."

5. Check that the stabilizer bar can pivot easily within the hooked ends of the keycap.

If any of the hooks or clips are bent, broken, or missing, replace the keycap.

If the hooks and clips are intact, re-use the keycap.

6. Check the rubber dome inside the keycap opening on the top case.

When the rubber dome is pressed and released, it should spring back upright.

If the rubber dome is off center or damaged, replace the top case.

7. With the stabilizer bar open, press the two ends of the slider bar into the slots in the keycap well so they snap into place.

8. Allow the dual-hinge mechanism to fold flat, and use a black stick to make sure the hinged pieces are pushed farthest away from the rubber dome (this is a tiny movement).

9. Carefully lower the keycap onto the top case, and press down on the center of the key until the keycap snaps into place.